Dandruff is directly related to fat intake . If you take you fate on the daily basis then surely you would have more dandruff. So cut your fat intake on the daily routine and dandruff will be vanished.
My experience is the opposite. Perhaps the type of fat is a factor? I find that raw marrow, suet and egg yolks reduces my dandruff and dry skin. Eating carbs other than raw fermented honey increases it for me, whereas the raw fermented honey actually decreases it. So for me it's not just a matter of fat vs. carbs--it's a bit more complex when taking into account the beneficial effect on my skin of the honey. I suspect that the raw fermented honey helps my skin because of antinfungal and possibly probiotic effects. On the downside, I noticed the past several days that my teeth are getting slightly looser since I've been eating more raw honey, so I've been cutting back somewhat again.
There are individual factors too, like genetics, disorders of metabolism and digestion, etc. For example, I've noticed that people who don't digest fat well tend to report more problems when they eat plentiful fat than those who report digesting it well. Every individual is different in some way.
Satya of Dirty Carnivore also reports that her dry skin improved on a low-carb, high-fat diet and worsens again if she eats too much plant food:
http://forum.dirtycarnivore.com/index.php/topic,949.msg50247.html#msg50247